---
id: CVE-2026-5267
title: |-
  Ciena Navigator Network
  Control Suite (NCS) contains an information exposure vulnerability in an
  event-streaming API that does not properly enforce authentication
summary: |-
  Ciena Navigator Network
  Control Suite (NCS) contains an information exposure vulnerability in an
  event-streaming API that does not properly enforce authentication. An
  unauthenticated attacker with network access to the affected service c…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-306
vendor: Ciena
product: Navigator NCS
affected:
  - navigator_ncs 7.2 and any older release
  - navigator_ncs 7.2-P01 through 7.2-P07
  - navigator_ncs 8.0
  - navigator_ncs 8.0-P01 through 8.0-P06A
  - navigator_ncs 8.1
  - navigator_ncs 8.1-P01 through 8.1-P06
  - navigator_ncs 8.2
  - navigator_ncs 8.2-P01 through 8.2-P06
  - navigator_ncs 9.0
  - navigator_ncs 9.0-P01 through 9.0-P05A
  - navigator_ncs 9.1
  - navigator_ncs 9.1-P01 through 9.1-P05
  - navigator_ncs 9.2
  - navigator_ncs 9.2-P01 through 9.2-P02
  - navigator_ncs 10.0
  - navigator_ncs 10.0-P01 through 10.0-P01B
published: '2026-09-25'
updated: '2026-09-25'
sourceUpdated: '2026-09-25T21:17:23.633'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-5267'
references:
  - url: 'https://www.ciena.com/product-security'
    label: 7bd90cf1-1651-495e-9ae8-9415fb3c9feb
tags:
  - nvd
  - cve.org
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-25T20:40:10.302755Z'
ingestedAt: '2026-09-25T20:17:49.419Z'
---

## Overview

Ciena Navigator Network
Control Suite (NCS) contains an information exposure vulnerability in an
event-streaming API that does not properly enforce authentication. An
unauthenticated attacker with network access to the affected service could
access the event stream and potentially obtain sensitive information.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.